FIELD OF THE INVENTION
The present invention relates to a photographic film having a novel bar code recorded in a different position using the standardized DX coding systems to represent additional information. More particularly, relates to a method of acquiring additional information for performing image processing by reading the novel bar code from the photographic film.
A photoprinter is an apparatus where an image taken with a camera and recorded on a photographic film such as a negative or reversal film (which are hereinafter referred to simply as "film") is printed on photographic paper such as color paper. It is required with the photoprinter that the photographic paper be finished to a print reproducing a high-quality image. To meet this requirement, the conventional analog photoprinter of an areal exposure type performs photometry on the image carried on a film, and printing conditions such as color filter conditions and the amount of exposure that are necessary for printing an image with appropriate colors and densities are determined on the basis of the obtained photometric data. The Assignee recently put a digital photoprinter on the market as an advanced model that performs digitally controlled laser exposure. With this photoprinter, the image carried on a film is photoelectrically read pixel by pixel to produce digital image data, on the basis of which printing conditions such as set-up and image processing conditions are determined in such a way as to print an image of appropriate colors and densities.
However, the emulsion used on films and their base density differ not only between film manufacturers but also between film types. Therefore, when photographic printing is to be done, just determining the printing conditions from photometric and digital image data is insufficient to produce an image having appropriate color and density balances. Hence, the image processing conditions and the printing conditions are currently determined based on the film manufacturer and the film type, in addition to the photometric and digital image data.
Under the circumstances, currently used photographic films such as negatives and reversals, particularly those of 135 size, have various kinds of bar codes marked in the edge portion as trade standards; they include a DX bar code that represents film information such as film manufacturer, film type and emulsion number (the DX bar code is hereinafter referred to simply as "DX code"), an expanded DX bar code which, besides including the above film information, adds the information about frame number in order to provide a back print of the frame number of the film for a finished print (the expanded DX bar code is hereinafter referred to simply as "expanded code"), and an FNS code which represents the frame number. These codes can be read automatically by a dedicated bar code reader.
FIG. 10A shows an example of the location DC where the DX code DX or the expanded DX code (DXe) is recorded on a negative film of 135 size, as well as the location FN where the (FNS) code FNS is recorded on the same film. FIGS. 10B, 10C and 10D show an example of the (DX) code DX, the expanded DX code (DXe) and the FNS code (FNS).
As shown in FIG. 10A, if the negative film of 135 size F0 is placed with the emulsion coated side facing down and with the frame number increasing from left to right, the expanded DX code DX or the expanded DX code DXe is recorded on the bottom edge. Namely, the DX or DXe codes are recorded in the edge region DC under bottom perforations P, in two locations in an image region GA of a common full-size frame. On the other hand, FNS is recorded in the edge region FN above top perforations P, in two locations in the image region GA. Hence, these standardized codes are recorded one by one in an image region of a half-size frame. Since the expanded DX code contains a portion representing the frame number, the code FNS is not recorded when the expanded DX code is recorded.
The DX code DX and expanded DX code DXe, as shown in FIGS. 10B and 10C, respectively, share the common feature of being a dual-track bar code consisting of two tracks, a clock track Tc in top and a data track Td at bottom. The DX code DX and expanded DX code DXe are bar codes consisting of 23 and 31 bits, respectively. Each bar code comprises, from left to right, a 6-bit entry pattern S1 representing the beginning of a bar code sequence, a 7-bit film-product-class identification array S2 representing film manufacturer, film type and the like, a 1-bit unassigned bit S3, a 4-bit film-specifier-array representing film's emulsion number and the like, a 1-bit parity bit S5 and a 4-bit exit pattern S6 representing the end of the bar code sequence. The expanded DX code DXe additionally includes 8 bits consisting of a 7-bit frame number array S7 and a 1-bit second unassigned bit S8 and which are interposed between the film-specifier-array S4 and the parity bit S5 in the DX code DX.
The FNS (film number system) code FNS, as shown in FIG. 10D, comprises, from left to right, an entry pattern S9 consisting of one wide bar followed by one narrow space, a frame number sequence S10 consisting of five bars elements interleaved with four space elements, three of these nine elements being wide and the remaining six being narrow, and an exit pattern S11 consisting of one narrow space followed by one narrow bar.
The standardized codes such as the above-described DX code DX, expanded DX code DXe and FNS code FNS provide film information such as film manufacturer, film type and emulsion number and by setting the conditions for printing and image processing the photographic paper in accordance with the film, one can produce finished prints that have been subjected to appropriate processing.
In fact, however, the quality of the image recorded on a photographic film largely varies with the model of the camera used to take the picture, the type of the taking lens, the characteristics of the photographic film on which the image was recorded and other factors. Consider, for example, the image recorded with a comparatively low-price camera such as a film with lens or a compact camera.
Generally speaking, the image, as compared with that recorded with a quality camera such as a single-lens reflex camera, suffers comparatively high levels of overall image blurring, decrease in the amount of exposure in the edge of image field, decrease of contrast, distortion of images such as the subject of interest, and cross color.
The deterioration in the quality of the image reproduced on prints is particularly pronounced when the image taken with a low-price camera is outputted as a print and factors that contribute to this phenomenon include the lateral chromatic aberration and distortion that are caused by the poor performance of the lens fitted on the camera used to record the image. A color image is formed of three primary colors, red (R), green (G) and blue (B) and due to the slight wavelength-dependent differences in the refractive index (imaging magnification) of the lens, the imaging magnification of the three light components, R, G and B, varies to cause "lateral chromatic aberration". As a result, the image recorded on a film will have color mismatch upon reproduction. In order to record a satisfactory image, a plane normal to the optical axis must be correspondingly imaged on an imaging plane. In fact, however, ordinary lenses suffer an aberration called "distortion". The image recorded on a film will accordingly be distorted upon reproduction.
If the image itself that is recorded on a photographic film has deteriorations in quality such as blurring and distortion, the problem cannot be dealt with by such measures as the correction of the amount of exposure and the print quality cannot be improved beyond a certain limit. This problem has become particularly noticeable in recent years as manufacturers offer cameras of lower price as exemplified by films with lens and compact cameras and as users prefer photographic films of higher speed; the deterioration in the quality of images on photographic films that is attributable to the model of the camera used to take pictures, the type of the taking lens, the characteristics of the photographic film and other factors is a direct cause of the substantial decrease in the quality of photographic prints and the like that are prepared by photoprinters.
Under the circumstances, the Assignee filed Japanese Patent Application No. 92804/1996 to propose a photographic processing apparatus and method that enable consistent production of high-quality images in a manner independent of the model of the camera used to take pictures, the type of the taking lens, the characteristics of the photographic film and other factors. However, the method specifically disclosed in the application for acquiring the information about camera model, lens type and film characteristics is by the operator's entering the information via a keyboard or the like or by reading magnetically recorded information and not by reading the information that has been recorded optically on the film. The specification of Japanese Patent Application No. 92804/1996 includes statements to the effect that the photographic film may be provided with an optical record such as bar codes and that the information optically recorded on the photographic film is read. However, there is no disclosure at all as to what information is recorded in what manner using what kinds of bar codes or the like and in what locations on the photographic film, nor is there any indication as to how the recorded bar codes or the like can be read and what kind of information is acquired.
When preparing prints, irrespective of whether they are simultaneous prints (i.e., print images prepared simultaneously with the development of a film) or re-prints (i.e., print images prepared to meet the request of a second order of the user), the most appropriate print is finished in accordance with not only the film information including film manufacturer, film type and emulsion number but also other features such as camera model, lens type and film characteristics. A frequent problem with this practice is that the re-print cannot be finished to the same quality as the simultaneous print. This is because the printing and image processing conditions employed in the making of the simultaneous print are not usually saved and, if they are saved, it is difficult, often impossible, to identify the saved conditions from the frames of a film for which the second order for re-printing has been placed. As a result, the printing and image processing conditions employed in the making of a re-print become different from those used in the making of the simultaneous print.